Games as Simulations
World of Warcraft is a large scale MMO with 1.5 million active users in 2005. Inside the game there are cities where thousands of players gathered and interacted with each other and hundreds more NPC’s doing commerce and meeting other players. Between cities there were paths for players to take to get to their next quest or the next city. Players spent real life hours in these fictional economies and meeting areas.
In September 13, 2005 a glitch came with the Zul’Gurub expansion that allowed researchers to observe something that rarely happens in the real world. A pandemic hit the World of Warcraft.
In 2007 Nina Hefferman who specializes in computer modeling of infectious diseases and Eric Lofgren published a paper in the Lancet detailing the event and its parallels to real world human responses disasters like pandemics and possibly even terrorist attacks.
The disease
Blizzard Entertainment the publisher of World of Warcraft released the expansion with a boss raid. The boss infected players with a status effect called Corrupted Blood that lasted until the player was cleansed by another player or died. The debuff was highly contagious, passed on to other players in their faction with a 100% transmission rate for everyone within 2 meters of the player. Infected players would lose health points slowly but would show no other signs of illness until the character died suddenly.
The code for the disease was never supposed to reach non-playable characters, the bank teller, the auction house dealer, the flight point terminal. NPC characters have much more stamina to weather the disease making their rounds across the city with no outward effects. Players didn’t know to stay away from them until often it was too late. In effect the NPC characters were asymptomatic carriers of the disease. The disease once hidden in NPCs was nearly impossible to eradicate by healers in the game itself.
Transmission
Researchers have been trying to model rare but dangerous events like pandemics for years. However the data on actual pandemics is exceedingly rare. It is hard to model how people will respond. Fefferman and her colleagues say “studying the actions of the millions of real people invested in World of Warcraft and other online worlds could substantially boost the reality quotient of disease simulators.”
The way the disease was transmitted to its first human hosts once outside the zone, the disease vector, mimics real world pandemic scenarios. Corrupted Blood had a vector through in game animals. Pets could be summoned outside and infect several players and NPC’s before anyone would notice. Real life vectors include chickens which pass avian flu to farmers to the cities where those farmers sold their goods.
Active Response
The Zul’Gurub raid zone was the hardest challenge in the game at the time so the Corrupted Blood infection was meant to hit very hard. It wasn’t meant to kill off the highest level players, at least not immediately, but it took a deadly toll on anyone below max level.
In response, community members posted players outside city entrances warning low level players to stay away from the city until the disease was under control inside. Healer players that were healthy enough treated the sick inside cities. Players created quarantines where outbreaks were doing the most harm.
Healers checked NPC’s across the cities, treating many hundreds of them on the chance that they received the disease but were not showing symptoms. Unlike in many real world scenarios treatment was very cheap. Players paid a tiny bit of mana resources and could afford to randomly distribute it to people who might not have needed treatment. Spread across hundreds of NPC’s in each of dozens of cities even cheap treatment strained their resources that could’ve gone to vulnerable players.
Active Sabotage
Players would also flag themselves as sick in hopes that players that were vulnerable would stay away. This system worked initially however quickly broke down as “griefers” players who revel in the chaos and breakdown of the system would intentionally spread the disease to unflagged players. This lead several uninfected to flag themselves as infected to keep the griefers at bay which undermined the whole point.
Once the community figured out the disease vector, malicious players would intentionally bring the disease to uninfected cities. Players would sneak past quarantine lines and hide the infected where healers would not easily find them.
Criticisms of using a game to simulate deadly plagues
Even though it’s clear that a game world is clearly different from the real world, there were plenty of parallels to draw and researchers were eager for data points about where the disease spread, how, how quickly, what worked and what didn’t. However it was clear that the low stakes effect the outcome. In Warcraft you aren’t losing your character, or your life. They come back fine, if inconvenienced.
For some there was the curiosity factor. Some uninfected players ran into cities to see what was happening. Some players welcomed the glitch calling it the games first “true world event” and remembering it fondly as “the day the plague wiped out Ironforge.” It is certainly one of the most memorable events in World of Warcraft history.
